The National September 11 Memorial & Museum (branded as 9/11 Memorial and 9/11 Memorial Museum) is the principal memorial and museum commemorating the September 11 attacks of 2001, which killed nearly 3,000 people, and the World Trade Center bombing of 1993, which killed six. The memorial is located at the World Trade Center site, on the former location of the Twin Towers, which were destroyed during the attacks. The World Trade Center Memorial Foundation was renamed the National September 11 Memorial & Museum at the World Trade Center in 2007.

The Royal Observatory just announced its Astronomy Photographer Of The Year 2013 winners. Australian photographer Mark Gee was chosen among a thousand amateur and professional photographers around the globe to win the top title. His work is part of an exhibition of the winning photographers, which opened on Sept. 19 at the Royal Observatory Greenwich. The Royal Observatory shared with us the winners and notable mentions of the competition. Their descriptions of the prizewinners can be found below the images.

A Snowboarder participates in a waterslide contest, which consists of gliding over a water pool embedded in snow, during the closing event of the ski resort of Nendaz, southwestern Switzerland, Monday, April 21, 2014. (Photo by Maxime Schmid/AP Photo/Keystone)

“The Siege of Sidney Street, popularly known as the “Battle of Stepney”, was a notorious gunfight in London's East End on the 2nd of January 1911. Preceded by the Houndsditch Murders, it ended with the deaths of two members of a supposedly politically-motivated gang of burglars supposedly led by Peter Piatkow, a.k.a. “Peter the Painter”, and sparked a major political row over the involvement of the then Home Secretary, Winston Churchill”. – Wikipedia

Photo: Scots Guards and police on duty during the “Siege of Sidney Street” in east London. (Photo by Central Press/Getty Images). 3rd January 1911

Miss Earth 2016 candidates wearing environmental statement sashes lineup during a press presentation in Manila, Philippines, 11 October 2016. Eighty three young women from around the globe converged in Manila for the international beauty event. Miss Earth is a pioneering beauty pageant that serves as a vehicle for environmental advocacy. (Photo by Mark R. Cristino/EPA)

A woman overcome by emotion after an aftershock hit the area, is carried by a relative to the general hospital in Port-de-Paix, Haiti, Sunday, October 7, 2018. A magnitude 5.2 aftershock struck Haiti on Sunday, even as survivors of the previous day's temblor were sifting through the rubble of their cinderblock homes. The death toll stood at 12, with fears it could rise. (Photo by Dieu Nalio Chery/AP Photo)

Models showcase Valentine's Day underwear celebrating the results of a recent survey revealing that men find the lingerie, boxer shorts and vests, the biggest turn on ahead of February 14 Valentine celebrations, at Waterloo on February 2, 2006 in London, England. (Photo by Gareth Cattermole/Getty Images)

Body builders preparing at the backstage during the Bodybuilding Cup in Kiev, Ukraine on November 7, 2015 which includes classic bodybuilding, physicist and body fitness and bikini in the competition. (Photo by Nazar Furyk/Pacific Press)